U.S. patent application number 12/276887 was filed with the patent office on 2009-06-18 for smart key system using lf antennas of tpms.
This patent application is currently assigned to HYUNDAI MOTOR COMPANY. Invention is credited to Eun Hee Kim.
Application Number | 20090153317 12/276887 |
Document ID | / |
Family ID | 40752441 |
Filed Date | 2009-06-18 |
United States Patent
Application |
20090153317 |
Kind Code |
A1 |
Kim; Eun Hee |
June 18, 2009 |
SMART KEY SYSTEM USING LF ANTENNAS OF TPMS
Abstract
The present invention provides a smart key system using Low
Frequency (LF) antennas of a Tire Pressure Monitoring System
(TPMS), in which a Central Processing Unit (CPU) installed inside a
vehicle control locking modules of respective doors to be opened or
locked in response to an open/close signal from a smart key
configured to transmit/receive a wireless signal unique to the
vehicle. A plurality of antennas are installed on the vehicle for
receiving a low frequency control signal transmitted from the smart
key. One or more of the antennas are the LF antennas used for the
TPMS of the vehicle.
Inventors: |
Kim; Eun Hee; (Gyeonggi-do,
KR) |
Correspondence
Address: |
EDWARDS ANGELL PALMER & DODGE LLP
P.O. BOX 55874
BOSTON
MA
02205
US
|
Assignee: |
HYUNDAI MOTOR COMPANY
Seoul
KR
|
Family ID: |
40752441 |
Appl. No.: |
12/276887 |
Filed: |
November 24, 2008 |
Current U.S.
Class: |
340/447 |
Current CPC
Class: |
E05B 77/48 20130101;
G07C 9/00309 20130101; B60C 23/0408 20130101; G07C 9/00944
20130101; B60R 25/245 20130101; G07C 2009/00793 20130101 |
Class at
Publication: |
340/447 |
International
Class: |
B60C 23/00 20060101
B60C023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 12, 2007 |
KR |
10-2007-0129288 |
Claims
1. A smart key system using Low Frequency (LF) antennas of a Tire
Pressure Monitoring System (TPMS), in which a Central Processing
Unit (CPU) installed inside a vehicle performs control such that
locking modules of respective doors are opened or locked in
response to an open/close signal from a smart key configured to
transmit/receive a wireless signal unique to the vehicle, the smart
key system comprising: a plurality of antennas installed on the
vehicle, and configured to receive a low frequency control signal
transmitted from the smart key in a Radio Frequency (RF) signal
form; and a low frequency driver configured to separate a control
signal for the locking modules from the RF signal input to the
antennas, and apply the control signal to the CPU; wherein one or
more of the antennas are the LF antennas used for the TPMS of the
vehicle.
2. The smart key system as set forth in claim 1, wherein the
antennas comprise internal antennas mounted inside the vehicle, and
the LF antennas of the TPMS mounted on respective tire wheels.
3. The smart key system as set forth in claim 1, wherein: the
antennas transmit a wake-up signal to the smart key if a command to
open/close the locking modules is detected in an ignition-off state
of the vehicle; and the CPU performs control such that the locking
modules are opened or closed if the smart key is authenticated.
4. The smart key system as set forth in claim 1, wherein the LF
antennas of the TPMS apply to the CPU through a low frequency
driver pressure information received from pressure sensors
installed on respective tire wheels at corresponding locations in
an ignition-on state of the vehicle.
5. The smart key system as set forth in claim 1, wherein: the
antennas comprise internal antennas mounted inside the vehicle, and
the LF antennas of the TPMS mounted on respective tire wheels; and
the low frequency driver comprises a first LF driver for separating
the control signal for the locking modules from the RF signal input
to the antennas, and then apply the control signal to the CPU, and
a second LF driver for applying to the CPU tire pressure
information input to the LF antennas.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims under 35 U.S.C. .sctn.119(a)
priority to Korean Application No. 10-2007-0129288, filed on Dec.
12, 2007, the disclosure of which is incorporated herein by
reference in its entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates generally to a smart key
system, and, more particularly, to a smart key system in which Low
Frequency (LF) antennas of a Tire Pressure Monitoring System (TPMS)
can be used for the smart key system.
[0004] 2. Background Art
[0005] With the improvement in the standard of living, the
popularization of privately owned cars has increased, and thus
privately owned cars have established themselves as life
necessities. Therefore, research into devices for preventing
vehicles, including privately owned cars, from being stolen, and
into various techniques for opening the doors of a vehicle and
starting the engine of the vehicle has been steadily conducted.
Examples include a keyless entry method and a keyless start
method.
[0006] The keyless entry method refers to a method in which a
driver opens or locks vehicle doors without operating a separate
key or a remote controller. When a driver carries a key, the key
and a digital authentication device transmit/receive data
therebetween. If the data is verified, the locking modules of the
doors are automatically operated.
[0007] In such a system, a smart key is used. The smart key
internally includes a device for transmitting/receiving
authentication information for a vehicle and a Radio Frequency (RF)
signal, and a plurality of antennas are provided inside and outside
a vehicle so as to communicate with the smart key.
[0008] In order to implement the smart key system, up to, for
example, 10 antennas, each having low frequency characteristics
(125 kHz or 134 kHz band), are used.
[0009] The antennas of the smart key system are used to detect a
smart key outside a vehicle. Here, radio waves generated fall
within a distance of 1 m from the vehicle, so that the detection of
and communication with the smart key can be performed within this
distance.
[0010] Meanwhile, antennas employing a low frequency method are
used in a TPMS capable of measuring the tire pressure of a vehicle
in real time and notifying a driver of it.
[0011] Each tire is provided with a pressure sensor for measuring
internal pressure, and each pressure sensor is provided with an LF
antenna (Initiator) for transmitting pressure information in a
wireless signal form. The pressure sensor operates only when the
engine of the vehicle is started.
[0012] FIG. 1 is a view showing the locations of respective
antennas installed in a prior art smart key system and a TPMS.
FIGS. 2 and 3 are block diagrams showing the respective
configurations of the prior art smart key system and the TPMS.
[0013] As shown in FIG. 1, respective antennas 23 and 33 for the
smart key system and TPMS are installed on predetermined portions
of the side surface (e.g., door handles and wheel guides) of a
vehicle.
[0014] The smart key system employs door handle antennas 23
installed inside the respective door handles of the vehicle and
configured to monitor the side surfaces of the vehicle, indoor
antennas 24 installed on the indoor ceiling or back seats of the
vehicle and configured to monitor the inside of the vehicle, and a
bumper antenna 25 installed inside a rear bumper and configured to
monitor the rear of the vehicle.
[0015] Each of the antennas 23, 24, and 25 transmits a signal used
to wake up a smart key 26, and allows the doors of the vehicle to
be opened or locked using authentication information returned from
the smart key.
[0016] Further, in the case of the TPMS, a pressure sensor 35,
installed in each tire, measures the pressure of the tire, and then
transmits the measured pressure to the LF antenna 33 using an LF
transmitter 34, so that pressure information is transmitted to a
Central Processing Unit (CPU) 31, thereby notifying the vehicle
driver of the pressure information. For this purpose, the LF
antenna 33 periodically or non-periodically transmits a signal used
to wake up the corresponding pressure sensor 35.
[0017] However, although all the antennas 23, 24, and 25, used for
the smart key system, and the LF antennas 33, used for the TPMS,
use the same frequency and the configurations of the hardware
thereof are the same, the antennas 23, 24, and 25 and the LF
antennas 33 are separately installed for the two separate systems,
thereby increasing manufacturing costs.
[0018] The above information disclosed in this the Background
section is only for enhancement of understanding of the background
of the invention and therefore it may contain information that does
not form the prior art that is already known in this country to a
person of ordinary skill in the art.
SUMMARY
[0019] Accordingly, the present invention has been made keeping in
mind the above problems occurring in the prior art, and an object
of the present invention is to provide a smart key system in which
the LF antennas of a TPMS are used instead of the door handle
antennas of a smart key system, thereby reducing manufacturing
costs.
[0020] In one aspect, a smart key system using the Low Frequency
(LF) antennas of a Tire Pressure Monitoring System (TPMS), in which
a Central Processing Unit (CPU), installed inside a vehicle,
performs control such that locking modules of respective doors are
opened or locked in response to an open/close signal from a smart
key configured to transmit/receive a wireless signal unique to the
vehicle, the smart key system including a plurality of antennas
installed on the vehicle, and configured to receive a low frequency
control signal transmitted from the smart key in a Radio Frequency
(RF) signal form; and low frequency driver configured to separate a
control signal for the locking modules from the RF signal input to
the antennas, and apply the control signal to the CPU; wherein one
or more of the antennas are the LF antennas used for the TPMS of
the vehicle.
[0021] The antennas include internal antennas mounted inside the
vehicle, and the LF antennas of the TPMS mounted on respective tire
wheels.
[0022] The antennas transmit a wake-up signal to the smart key if a
command to open/close the locking modules is detected in the
ignition-off state of the vehicle; and the CPU performs control
such that the locking modules are opened or closed if the smart key
is authenticated.
[0023] The LF antennas of the TPMS apply to the CPU through a low
frequency driver pressure information received from pressure
sensors installed on respective tire wheels at corresponding
locations in the ignition-on state of the vehicle.
[0024] The antennas include internal antennas mounted inside the
vehicle, and the LF antennas of the TPMS mounted on respective tire
wheels; and the low frequency driver includes a first LF driver for
separating the control signal for the locking modules from the RF
signal input to the antennas, and then apply the control signal to
the CPU, and a second LF driver for applying to the CPU tire
pressure information input to the LF antennas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The above and other objects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0026] FIG. 1 is a view showing the locations of antennas
separately installed in a smart key system and a TPMS according to
the prior art;
[0027] FIGS. 2 and 3 are block diagrams showing the configurations
of the smart key system and the TPMS according to the prior
art;
[0028] FIG. 4 is a block diagram showing the configuration of a
smart key system according to the present invention; and
[0029] FIG. 5 is a flowchart showing the flow of the operation of
the smart key system according to the present invention.
DETAILED DESCRIPTION
[0030] Reference now should be made to the drawings, in which the
same reference numerals are used throughout the different drawings
to designate the same or similar components.
[0031] A smart key system using LF antennas of a TPMS (hereinafter
referred to as `smart key system`) according to embodiments of the
present invention will be described in detail with reference to the
attached drawings below.
[0032] FIG. 4 is a block diagram showing the configuration of the
smart key system according to an embodiment of the present
invention.
[0033] As shown in FIG. 4, a smart key system 100 includes a CPU
102 for controlling the operation of locking a door and detecting
tire pressure, and first and second LF drivers 104 and 106 for
transmitting/receiving signals used to operate the respective
systems thereof. Of course, the first and second LF drivers 104 and
106 may be implemented as an integrated low frequency driver.
[0034] In FIG. 4, the first LF driver 104 is used to operate the
smart key system and the second LF driver 106 is used to operate
the TPMS. The second LF driver 106 may be realized as a separate
driver.
[0035] The first LF driver 104 is connected to LF antennas 112 and
internal antennas such as an indoor antenna 108 and a bumper
antenna 110.
[0036] As described above, the indoor antenna 108 is installed on
the ceiling or each of back seats of a vehicle, and the bumper
antenna 110 is installed inside a back bumper.
[0037] The second LF driver 106 is connected to the LF antennas
112. As shown in FIG. 4, for example, the LF antennas can be
consisted of four antennas, LF, RF, LR, and RR. Although not shown
in FIG. 4, the four LF antennas 112 are installed on four tire
wheels, respectively, and are configured to communicate using four
respective LF transmitters for transmitting pressure information
applied from pressure sensors, installed on the corresponding tire
wheels, and RF signals.
[0038] In particular, the LF antennas 112 are used for the highline
of the TPMS, and are configured to detect a tire the pressure of
which deviates from a predetermined level.
[0039] A driver can open a door or start an engine when he/she
approaches a vehicle while possessing a smart key 200.
[0040] The operation of this system according to an embodiment will
be described with reference to FIG. 5.
[0041] First, the smart key system 100 monitors the ignition-on
state of the vehicle at step S102. The TPMS monitors variation in
the pressure of each tire while a vehicle is traveling.
Accordingly, the LF antennas 112 for the TPMS are required to be
operated only in the ignition-on state. On the other hand, the
antennas for the smart key are required in the ignition-off state.
For this reason, the ignition-on state of the vehicle is monitored
first.
[0042] If the vehicle is in the ignition-off state, the first LF
driver 104 is driven to control the operation of locking doors at
step S104.
[0043] When the first LF driver 104 is driven, each of the indoor
antenna 108, the bumper antenna 110, and the LF antennas 112
transmits a smart key wake-up signal at step S106. That is, the LF
antennas 112 of the TPMS substitute for the prior art door handle
antennas 23.
[0044] When authentication information is input from the smart key
200 in response to the transmitted driving signals, the locking
modules (not shown) of the respective doors are open or locked
under the control of the CPU 102 at step S108.
[0045] On the other hand, if the vehicle is in the ignition-on
state, the second LF driver 106 is driven to monitor the pressure
of each tire at step S110.
[0046] When the second LF driver 106 is driven, each of the LF
antennas 112 transmits a driving signal to each of the pressure
sensors installed on the respective tires at step S112.
[0047] Further, since the pressure information, transmitted from
the respective pressure sensors, are applied to the CPU 102 through
the four LF antennas 112 and the second LF driver, the pressure of
respective tires can be measured at step S114.
[0048] According to the above-described smart key systems, the
number of antennas can be reduced, thereby reducing manufacturing
costs and simplifying the process of mounting antennas.
[0049] Although the preferred embodiments of the present invention
have been disclosed for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
* * * * *